Route the effects · SP-404MKII guide

7.1Basics

How buses and effects fit together

On the 404, an effect doesn’t belong to a sample or a pad. It sits on a bus, a path that audio travels along inside the unit. You choose which path each sound takes and which effect sits on each path, and between them those two choices decide what gets processed. Get this idea straight and the rest of the chapter falls into place.

The five paths

Bus	What feeds it	How you control it	What it’s for
BUS 1	Samples and external input you assign to it	The six effect keys and CTRLS, with BUS 1 selected on `BUS FX`	Effects you play with as you perform
BUS 2	Samples and external input you assign to it, plus everything from BUS 1 when `Routing` is `TYPE A`	The same keys and knobs, with BUS 2 selected on `BUS FX`	A second set of hands-on effects
DRY	Samples and external input you assign to it	It has no effect of its own	Sounds you want to keep away from the BUS 1 and BUS 2 effects
BUS 3	Everything leaving BUS 1 and BUS 2, plus DRY if you route it here	The `EFX SET` screen, not the effect keys	Master effects that shape the whole mix
BUS 4	Everything leaving BUS 3	The `EFX SET` screen, not the effect keys	Master effects that shape the whole mix

Think of it as three entrances and one exit. Every sound enters at BUS 1, BUS 2 or DRY, and each bus carries one effect at a time. What happens next depends on two settings: Routing decides how BUS 1 and BUS 2 connect, and DRY Routing decides where DRY rejoins the rest.

The route each sound takes

A sound on	With this setting	Travels through
BUS 1	`Routing` at `TYPE A` (serial)	BUS 1 → BUS 2 → BUS 3 → BUS 4 → output
BUS 2	`Routing` at `TYPE A` (serial)	BUS 2 → BUS 3 → BUS 4 → output
BUS 1	`Routing` at `TYPE B` (parallel)	BUS 1 → BUS 3 → BUS 4 → output
BUS 2	`Routing` at `TYPE B` (parallel)	BUS 2 → BUS 3 → BUS 4 → output
DRY	`DRY Routing` at `DRY`	Straight to the output, past every bus effect
DRY	`DRY Routing` at `BUS 3`	BUS 3 → BUS 4 → output

What this means in practice

In normal play, the six effect keys and CTRLS control BUS 1 or BUS 2, whichever one BUS FX has selected (Turn an effect on from the keys). BUS 3 and BUS 4 have no keys: you load them as a favourite on the EFX SET screen and edit them there (Load a saved BUS 3 and BUS 4 set-up, Set the effects on BUS 3 and BUS 4).
Selecting a bus on BUS FX doesn’t move any sound. To change where a sample goes, reassign it (Send each sample to a bus).
With TYPE A, an effect on BUS 2 also changes samples on BUS 1, because they pass through it on the way out. An effect on BUS 1 never touches samples on BUS 2 (Put BUS 1 and BUS 2 in series or in parallel).
BUS 3 and BUS 4 process everything coming from BUS 1 and BUS 2, so a change there affects the whole mix apart from anything on DRY that skips them.

From the community

Introducing the Roland SP-404MKII Creative Sampler and Effector
RolandChannel
Roland’s own 13-minute tour of the hardware, sampling, bus effects, patterns and DJ mode. It dates from the 2021 launch, so there’s no TR-REC, looper or side chain yet.

SP-404 Mk2 Beginner's Guide (Part 2): Effects, Busses, Routing, Resampling & Skipback
Chris Laps
Part 2 moves to effects, the difference between BUS 1–2 and BUS 3–4, routing, resampling, skip-back and input effects.

SP404 MK2 Bus Effects Explained! (Routing Tips + My Go-To Setup)
sunwarper
Explains Input FX, BUS 1–2 and BUS 3–4, gives effect ideas for each, and shares a go-to BUS 3–4 combination.

SP404 mk2 production tips/tricks/problem solving/bugsElektronauts — Owners swapping fixes and workflow ideas since 2022. Older posts can describe bugs that later updates fixed.

7.2Basics

Turn an effect on from the keys

This is the everyday way to use effects, and it’s built for playing live: six keys around the screen switch effects on and off, and three knobs change them while the sound runs. Everything here acts on BUS 1 or BUS 2, so a sample only responds if its route passes through the bus you’re working on (Send each sample to a bus).

Press BUS FX to choose the bus the keys and knobs will control. The key lights orange for BUS 1 and blinks orange for BUS 2.
Press an effect key: FILTER+DRIVE, RESONATOR, DELAY, ISOLATOR, DJFX LOOPER or MFX. The effect comes on for the selected bus.
Turn CTRLS to change how the effect sounds (Edit an effect and keep your settings).
Press the lit or blinking effect key to turn the effect off again.

Key combinations

BUS FX: Switches the effect keys and knobs between BUS 1 and BUS 2.
EFFECT: Turns that effect on or off for the selected bus.
Hold REMAIN + BUS FX: Swaps the effects on BUS 1 and BUS 2, keeping their settings.

The BUS SELECT screen shows the two buses side by side, each with its effect’s name or Bypass, and tells you whether BUS 3 and BUS 4 are on.

The first five keys each hold one effect: Filter+Drive, Resonator, Sync Delay, Isolator and DJFX Looper. You can reassign any of them (Put your own effects on the effect keys). The sixth, MFX, gets you the long MFX list (Pick any effect from the MFX list). Every effect’s controls are described in Filters and EQ and the sections after it.

From the community

SP-404MKII in 2026 | Everything You Need to Get Started
Gear4music Synths & Tech
Andy from Roland takes a beginner from banks and pads through resampling, effects, the step sequencer, skip-back and the looper. Filmed in 2026, so it matches a current unit.

SP-404MKII Creative Sampler and Effector Video Manual
Roland Cloud Academy
Roland product specialist PJ Bridger works through the unit in 93 minutes, with a chapter for almost every function. It was filmed at launch, so nothing added since then appears.

【SP-404MKII】EFFECTS / BUS FX・INPUT FX・DIRECT FX【How to Setup】
Roland ｜ローランド
A tidy run through BUS 1–4, Direct FX, Input FX, DRY routing, mute bus and effect grab. From Roland’s Japanese channel, so expect Japanese; YouTube offers auto-generated English captions.

Revealing my SP404-MK2 BUS HOT SAUCE!
SPVIDZ
One producer’s actual effect recipe, explained bus by bus, including what BUS 3 and 4 add.

7.3Basics

Apply an effect only while you hold its key

An effect key normally works as a latch: one press on, another press off. EFFECT GRAB makes it momentary instead, which is ideal for throwing an effect onto one beat or phrase and having it gone the moment you let go. It works with all six effect keys.

Hold VALUE.
Press and keep holding an effect key. The effect sounds on the selected bus.
Let go of the effect key. The effect stops.

Key combinations

Hold VALUE + EFFECT: Makes the effect momentary, so it sounds only as long as the key is down.

From the community

7.4Basics

Pick any effect from the MFX list

Five effect keys hold one effect each. MFX is different: it holds whichever effect you pick from a long list, and you can change your pick mid-performance. That one key is how you reach reverbs, vinyl simulators, stutters and most of what else the 404 offers.

Press BUS FX to select the bus you want the effect on.
Hold MFX. The list appears on the screen as a four-by-four grid, the same shape as the pads.
Keep holding and choose an effect: turn VALUE or CTRL 3, or press a PAD.
Let go of MFX. The effect comes on and its edit screen opens.
Turn CTRLS to change it. Hold VALUE as you turn them to reach any sub-parameters (Edit an effect and keep your settings).

Key combinations

Hold MFX + VALUE: Moves through the MFX list.
Hold MFX + CTRL 3: Moves through the MFX list.
Hold MFX + PAD: Chooses the effect at that position in the list.
MFX + DJFX LOOPER: Jumps to effect 17 onwards in the MFX list.
MFX + ISOLATOR: Jumps to effect 33 onwards in the MFX list.

The list as the pads see it

Effects	While holding `MFX`	In pad order
1–16	Press a `PAD`	`Scatter`, `Downer`, `Ha-Dou`, `Ko-Da-Ma`, `Zan-Zou`, `To-Gu-Ro`, `SBF`, `Stopper`, `Tape Echo`, `TimeCtrlDly`, `Super Filter`, `WrmSaturator`, `303 VinylSim`, `404 VinylSim`, `Cassette Sim`, `Lo-fi`
17–32	Press `DJFX LOOPER`, then a `PAD`	`Reverb`, `Chorus`, `JUNO Chorus`, `Flanger`, `Phaser`, `Wah`, `Slicer`, `Tremolo/Pan`, `Chromatic PS`, `Hyper-Reso`, `Ring Mod`, `Crusher`, `Overdrive`, `Distortion`, `Equalizer`, `Compressor`
33 onwards	Press `ISOLATOR`, then a `PAD`	`SX Reverb`, `SX Delay`, `Cloud Delay`, `Back Spin`, `DJFX Delay`

To choose the effect MFX is set to when you power on, change MFX TOP on the OTHER tab of the effect settings (Every effect setting).

From the community

10 Powerful SP-404-MK2 Shortcuts You NEED TO KNOW!
SPVIDZ
Ten held-button shortcuts filmed in 2026, from selecting pads silently to swapping bus effects and protecting a bank.

7.5Intermediate

Edit an effect and keep your settings

When you switch an effect on, its edit screen opens and CTRLS start controlling the three settings shown side by side. These are the main parameters. Depending on the effect, a second page of sub-parameters sits behind them, which you reach by holding VALUE as you turn the same knobs.

Key combinations

Hold VALUE + CTRLS: Edits the effect’s sub-parameters.
Hold REMAIN + EFFECT: Keeps the effect’s edit screen showing.
Press VALUE: Flips between main and sub-parameters, on effects that have both.With the edit screen locked
SHIFT + MARK: Stores the current main parameters on BUS 1 and BUS 2, so they survive a power-off.Hold for at least three seconds

Lock the edit screen

Hold REMAIN and press an effect key. The edit screen opens and stays put, instead of going back to the previous screen after several idle seconds.
Press VALUE to flip between main and sub-parameters, if the effect has both.
Press EXIT or REMAIN when you’re done.

What the 404 remembers after a power-off

Effect on	Main parameters	Sub-parameters
INPUT (Input FX)	Kept	Kept
BUS 1, BUS 2	Kept only if you save them with `SHIFT` + `MARK`	Kept
BUS 3, BUS 4	Kept	Kept

Some settings are also shared between effect slots. Sub-parameters are common to INPUT, BUS 1 and BUS 2: put the same effect on Input FX and on BUS 1, change a sub-parameter on the input, and BUS 1 takes the new value too. BUS 3 and BUS 4 share their parameters in the same way.

Effects on BUS 3 and BUS 4 are edited on their own tabs rather than from this screen (Set the effects on BUS 3 and BUS 4). To record your knob moves into a pattern, see Automate your effect moves.

From the community

7.6Basics

Send each sample to a bus

Because effects live on buses, this is how you decide which samples get which effect. Put the drums on DRY and a melodic loop on BUS 1, and a delay on BUS 1 only touches the loop. The same assignment decides what can drive or be ducked by side chain compression (Duck one bus with another using side chain).

Press BUS FX to select BUS 1 or BUS 2.
Press and hold REMAIN. The pads light up in colours that show where each sample goes.
Keep holding and press a pad. Each press switches that sample between the selected bus and DRY.
Let go of REMAIN.

Key combinations

Hold REMAIN: Shows each sample’s bus as a pad colour.Long press
Hold REMAIN + PAD: Sets which bus the sample on that pad is sent to.
Hold REMAIN + BANK: Sets the bus for every sample in a bank.

Factory pad colours

Colour	Bus
Orange	BUS 1
Green	BUS 2
White	DRY

To use different colours, change BUS COLOR in the pad settings (Every pad setting). External input is assigned separately (Decide where external audio goes).

From the community

Once you’ve resampled effects into a sample, hold REMAIN and press its PAD so it goes to DRY (white with the factory colours). It won’t get the same effects twice, which leaves BUS 1 and BUS 2 free for performing. via DimensionsTomorrow on Elektronauts

ROLAND SP-404 MK2 Review // 9 tips & ideas to make the most of it // Tutorial for the SP-404 MKII
loopop
A 50-minute tutorial and review from launch, with nine ideas and a list of pros and cons near the end. It predates TR-REC, so treat its sequencing chapter as out of date.

SP-404 MK2 BUS FX ROUTING Explained
Nonjuror
Serial versus parallel buses, assigning pads, and separate settings for performing and for beat making. From 2022, so there’s no side chain, but the routing it explains still applies.

7.7Intermediate

Cut the audio and leave the effect tails

MUTE BUS is a performance trick for breaks. It shuts off the audio going into the bus but leaves the effect running, so a reverb or delay carries on by itself. When you turn it off, your audio returns and the effect on the bus switches off at that moment, so you go from sound with effect, to tail only, to clean sound.

With a sound playing through a reverb or delay on the bus, press SHIFT + BUS FX. The screen shows MUTE BUS, and you hear only what the effect is still producing.
Press SHIFT + BUS FX again when you want the music back. The audio returns, and the effect is now off.

Key combinations

SHIFT + BUS FX: Mutes the audio going into the bus so only the effect is left; press again to bring the audio back and switch the effect off.

How much it mutes

Mute Bus: Found on the OTHER tab of the effect settings (Find your way around the effect settings). ALL mutes BUS 1 and BUS 2 together; BUS mutes only the one selected with BUS FX.Range ALL, BUS

From the community

7.8Intermediate

Find your way around the effect settings

Most of what isn’t a live key press lives on the EFX SET screen: how the buses connect, what’s on BUS 3 and BUS 4, side chain, and what the effect keys hold. Most settings on its tabs change the same way, so the steps below will get you through nearly all of them.

From the top screen, press SHIFT + PAD 16. Or press SHIFT + PAD 13 for the UTILITY MENU, turn VALUE to EFX SET and press VALUE.
Turn CTRL 3 to choose a tab.
Turn VALUE to reach a setting, then press VALUE so that its value highlights.
Turn VALUE to change the value, then press VALUE to set it.
Press EXIT to go back to the UTILITY MENU.

Key combinations

SHIFT + PAD 16: Opens the effect settings.

What’s on each tab

Tab	What you set there	Details
`FAVORITE`	How BUS 1 and BUS 2 connect, and which favourite BUS 3 and BUS 4 run	Put BUS 1 and BUS 2 in series or in parallel, Load a saved BUS 3 and BUS 4 set-up
`BUS 3`, `BUS 4`	The effect on each of those buses and its parameters	Set the effects on BUS 3 and BUS 4
`SIDE CHAIN`	The side chain compressor	Duck one bus with another using side chain
`DIRECT`	The effect held by each of the five dedicated keys	Put your own effects on the effect keys
`OTHER`	`Mute Bus`, `Input FX`, `Input Bus`, `DRY Routing` and `MFX TOP`	Cut the audio and leave the effect tails, Add an effect to what’s coming in, Decide where external audio goes, Put BUS 1 and BUS 2 in series or in parallel, Pick any effect from the MFX list

Every value on these tabs is listed in Every effect setting.

From the community

The Roland SP-404 MK II Deep Dive tutorial guide
XNB
Nearly two hours on projects, banks, patterns, playback modes and effects, with chapters to dip into. Uploaded just before 4.04, so there’s no looper or sound generator.

SP404 MKII Pad Shift Functions Explored
SPVIDZ
Goes through what each pad does with Shift held, from Fixed Velocity to EFX settings. Filmed at launch, but the pad layout hasn’t changed.

7.9Intermediate

Put BUS 1 and BUS 2 in series or in parallel

The Routing setting decides whether BUS 1 and BUS 2 are a chain or two separate lanes. With TYPE A, BUS 1 runs on into BUS 2, so sounds on BUS 1 pick up both effects while sounds on BUS 2 get only the second. With TYPE B, each bus processes only its own sounds. Either way, the result then goes on into BUS 3 and BUS 4.

Switch the routing

Open the effect settings (Find your way around the effect settings).
Turn CTRL 3 to the FAVORITE tab.
Press VALUE. Each press switches between TYPE A and TYPE B.
Press EXIT when you’re done.

Which to choose

TYPE A when you want to stack two effects on the same sounds. Put them on BUS 1 and they go through both.
TYPE B when you want independent treatments, so that an effect on one group of sounds never reaches the other. It’s also the one to use when a side chain source needs its own effect (Duck one bus with another using side chain).

A second setting, on the OTHER tab, decides what DRY means. At DRY, those sounds join at the very end and no bus effect touches them. At BUS 3, they join just before BUS 3, so they still skip BUS 1 and BUS 2 but go through your master effects with everything else.

Parameters

Routing: On the FAVORITE tab. Connects BUS 1 and BUS 2 in series (TYPE A) or in parallel (TYPE B).Range TYPE A, TYPE B
DRY Routing: On the OTHER tab. Where DRY sounds rejoin: after BUS 4 (DRY), or just before BUS 3 (BUS 3).Range DRY, BUS 3

From the community

Roland SP-404MKII review: Roland’s second coming shows the sampling world who’s bossMusicTech — William Stokes gives it 9/10, and is useful on how long the bus routing takes to click and why buses 1–2 and 3–4 feel different.

7.10Intermediate

Load a saved BUS 3 and BUS 4 set-up

BUS 3 and BUS 4 don’t switch on from a key. They run whatever is in the favourite you’ve loaded: one of 16 slots, each holding the effects for both buses along with all their settings. Favourites aren’t tied to a project, so a master chain you like can follow you from one project to the next.

Open the effect settings (Find your way around the effect settings).
Turn CTRL 3 to the FAVORITE tab.
Turn VALUE to choose FAVORITE 1–FAVORITE 16. The BUS 3 and BUS 4 effects come on as that slot has them. Choose Bypass to disable both buses.
Press EXIT when you’re done.

Parameters

FAVORITE: The slot BUS 3 and BUS 4 read their effects from. At Bypass both buses are out of action, so pick a number before you try to use them.Range Bypass, 1–16

To change what’s in a slot, see Set the effects on BUS 3 and BUS 4. For a whole chain worked through step by step, try Build a lo-fi master chain.

From the community

Roland SP404-MK2 - ESSENTIAL Customisations!
SPVIDZ
Setting up the 404 for speed: MFX buttons, bus colours, pad settings, bus favourites, pop-ups, skip-back time, count-in and the boot-up screen.

7.11Intermediate

Set the effects on BUS 3 and BUS 4

BUS 3 and BUS 4 come after BUS 1 and BUS 2, one after the other, so they’re the natural place for effects that shape the overall mix. You set them on tabs in the effect settings rather than with the effect keys, and you don’t have to save anything: each edit goes straight into the selected favourite.

Open the effect settings (Find your way around the effect settings).
Turn CTRL 3 to the FAVORITE tab, then turn VALUE to the slot you want to edit, FAVORITE 1–FAVORITE 16.
Turn CTRL 3 to the BUS 3 or BUS 4 tab.
Press VALUE so that the EFX Type value highlights.
Turn VALUE to choose an effect, then press VALUE to confirm it.
Turn VALUE to move the cursor to a row of parameters. Each row holds up to three, ready for the three knobs.
Turn CTRLS to change the values in that row.
Press EXIT when you’re done.

Key combinations

Hold VALUE + BUS FX: Turns the BUS 3 and BUS 4 effects off temporarily, without changing the FAVORITE setting.

Not every effect can go here. The EFX Type list includes Filter+Drive, Resonator, Sync Delay, Isolator and DJFX Looper, but not Stopper, Back Spin or the input-only effects. DJFX Delay is unclear: that list leaves it out, but Roland’s MIDI table for BUS 3 and BUS 4 includes it. The full list is in Every effect setting.

From the community

7.12AdvancedSystem 5.50+

Duck one bus with another using side chain

Side chain compression turns one bus down whenever another one gets loud. The bus being listened to is the source, and the bus being turned down is the target. The further the source goes past the threshold, the more the target drops. You can use this to make a kick cut through other low-end sounds, or push it further to make the mix breathe in time with the beat.

Set it up

Put the sound that should do the pushing on one bus, and the sounds that should duck on another (Send each sample to a bus).
Open the effect settings (Find your way around the effect settings) and turn CTRL 3 to the SIDE CHAIN tab.
Turn VALUE to reach a setting, then press VALUE.
Turn VALUE to choose the value, then press VALUE to set it.
Set SOURCE, then set TARGET to anything other than OFF. Side chain is now on.
Press EXIT when you’re done.

Parameters

SOURCE: The bus whose level sets off the ducking.Range DRY, BUS 1, BUS 2, BUS 3, BUS 4
TARGET: The bus that gets turned down. At OFF side chain does nothing; any other value switches it on.Range OFF, DRY, BUS 1, BUS 2, BUS 3, BUS 4
THRESHOLD: How loud the source must get before the target starts to drop. Mind the direction: a higher number means a lower threshold, so quieter source sounds will set it off.Range 0–255
RATIO: How hard the target gets pushed down once the source is past the threshold. Higher numbers go deeper, and at the extreme the target falls silent.Range 0–255
RELEASE: How long the target takes to recover. Higher numbers bring it back more gradually, so the ducking lingers after the source has fallen below the threshold.Range 0–255
GAIN: Make-up gain. Lifts the final output to win back the level that compression took away.Range 0.0dB–6.0dB

Make a kick cut through the mix

Pick a bus for the kick and make it the SOURCE. If you choose DRY as the source, the kick sample has to be on DRY.
Gather the sounds that crowd the kick’s frequencies on BUS 1 or BUS 2, and make that bus the TARGET.
Play the pattern. Set RATIO to its maximum and RELEASE to its minimum for now, then change THRESHOLD until you can hear where the compression begins.
Set RATIO to 100 and keep adjusting until the mix sounds natural.
If the kick is short and sharp, lengthen RELEASE so that the target doesn’t sound chopped off. As a rule, the faster the pattern, the shorter the release that sounds natural.
Raise GAIN to recover the level the compression takes from the target. The target always gets louder when the source stops, since nothing is being compressed any more.
If it still doesn’t sit right, step back and balance the volume of each sample (Change a sample’s pitch and speed) and the levels between buses. Side chain can’t replace a good balance.

From the community

Roland SP-404MKII V5.50 Firmware Update
RolandChannel
Five minutes on 5.50’s side chain compression: where the menu is, picking sources and targets, then threshold, ratio, release and gain.

SP-404MKII SIDECHAIN TUTORIAL (Threshold, Ratio & Release Explained!)
Nonjuror
Breaks down source, target, threshold, ratio, release and gain, then applies two contrasting settings to a real beat.

SP-404MKII side chain compression; #404day videosCDM — Peter Kirn’s write-up of 5.50, including which buses can be source and target.

7.13Intermediate

Put your own effects on the effect keys

The five dedicated effect keys don’t have to keep the effects printed on them. Give one the effect you use most and it’s a single press away, with no list to go through. This suits a live set, where you want your favourite effects under your fingers (Get ready to play live).

Open the effect settings (Find your way around the effect settings) and turn CTRL 3 to the DIRECT tab.
Turn VALUE to the key you want to change, using the table below. You can also press the effect key itself.
Press VALUE so that the value highlights.
Turn VALUE to choose the effect, then press VALUE to assign it.
Press EXIT when you’re done. The key now switches your chosen effect on and off.

Which setting belongs to which key

Key	Setting
`FILTER+DRIVE`	`Direct FX1`
`RESONATOR`	`Direct FX2`
`DELAY`	`Direct FX3`
`ISOLATOR`	`Direct FX4`
`DJFX LOOPER`	`Direct FX5`

The effects you can choose are listed in Every effect setting. MFX isn’t one of the five, as it already holds whichever effect you pick from its list (Pick any effect from the MFX list).

From the community

7.14Intermediate

Add an effect to what’s coming in

Input FX is a separate effect that only processes external input: whatever comes in through INPUT and LINE IN. It’s also the only way to use Auto Pitch, Vocoder, Harmony and Gt Amp Sim, which work nowhere else. The same parameters apply when you sample and resample (Set up a recording).

Choose the effect from the effect settings

Open the effect settings (Find your way around the effect settings) and turn CTRL 3 to the OTHER tab.
Turn VALUE to Input FX, then press VALUE.
Turn VALUE to choose the effect, then press VALUE to set it.
Press EXIT when you’re done.

Choose and edit it from the input settings

Open the input setting screen: press SHIFT + EXT SOURCE (Plug in a synth, mic or guitar), or in sample mode press REC and then RECORD SETTING.
Press VALUE. The INPUT FX Setting screen opens.
Turn VALUE to EFX Type, then press VALUE.
Turn VALUE to choose the effect, then press VALUE to set it.
Turn VALUE to reach the parameter you’re after.
Turn CTRLS to edit it.

What you can use

Group	Effects
Input FX only	`Auto Pitch`, `Vocoder`, `Harmony`, `Gt Amp Sim`
Also available on the buses	`Chorus`, `JUNO Chorus`, `Reverb`, `TimeCtrlDly`, `Chromatic PS`, `Downer`, `WrmSaturator`, `303 VinylSim`, `404 VinylSim`, `Cassette Sim`, `Lo-fi`, `Equalizer`, `Compressor`
No effect	`Bypass`

Each effect’s controls are described in the library: the voice effects in Pitch and voice effects and the amp in Drive and distortion. After Input FX, the sound goes on to the bus you choose in Decide where external audio goes.

From the community

Hearing noise with nothing plugged in? It’s probably an effect rather than a fault. Turn GAIN right down, set the input effect to bypass with SHIFT + EXT SOURCE, make sure nothing is lit on BUS 1 or BUS 2, and set FAVORITE to Bypass with SHIFT + PAD 16. via NearTao on SP-Forums

Vocal FX Walkthrough - SP-404MK2
ZEALE
Connecting a microphone, routing it, and using input and bus effects on vocals for stage and studio. From 2021.

7.15Intermediate

Decide where external audio goes

Anything plugged into INPUT or LINE IN can go through the same buses as your samples. Send a synth or a mic to BUS 1 and the effect keys work on it as they do on a sample, or send it to DRY to keep it clear of the BUS 1 and BUS 2 effects. For getting the sound in to begin with, see Plug in a synth, mic or guitar.

Open the effect settings (Find your way around the effect settings) and turn CTRL 3 to the OTHER tab.
Turn VALUE to Input Bus, then press VALUE.
Turn VALUE to choose the bus, then press VALUE to confirm it.
Press EXIT when you’re done.

Key combinations

Hold REMAIN + EXT SOURCE: Sets which bus the external input goes to.

That shortcut works in sample mode. As you use it, the EXT SOURCE light shows the choice: lit for BUS 1, blinking for BUS 2 and dark for DRY.

Parameters

Input Bus: On the OTHER tab of the effect settings. Where INPUT and LINE IN are sent. On DRY the BUS 1 and BUS 2 effects leave them alone.Range DRY, BUS1, BUS2
USB In: On the GENERAL tab of the SYSTEM screen (Every system setting). LINE IN merges USB audio in ahead of Input FX so that it follows the input bus. MIX OUT adds it to the final output with no effects.Range LINE IN, MIX OUT

For sending audio from a computer or phone into the unit, see Bring in audio from a computer or phone. For where all of this sits in the overall signal path, see How sound travels through the 404.

From the community

If USB audio plays whether EXT SOURCE is on or off, USB IN is set to MIX OUT, which skips the input section. Set it to LINE IN if you want EXT SOURCE to control it. via NearTao on YouTube